CHAPTER 4
TrueType Fonts
TrueType Font Dictionary Entries 81
Table 4-2 Type 42 key-value pairs common to all PostScript font dictionaries
Key Type Semantics
Encoding array
Required. An array of 256 names that maps character codes
(integers) to character names.
Note that Apple TrueType fonts have an encoding vector different
from the StandardEncoding used by Type 1 fonts.
Conventional value: derived from information in the 'sfnt'
post table.
FontBBox array
Required. An array of four numbers in the character coordinate
system giving lower-left x, lower-left y, upper-right x, and
upper-right y of the font bounding box.
To ensure compatibility with certain versions of the LaserWriter
driver, this array should have the executable attribute.
FontInfo dictionary
Optional. This entry is for information only. FontInfo is not
used by the PostScript interpreter. See Table 4-5 for the entries
that can be included in this dictionary.
FontMatrix array
Required. Transformation matrix for transforming the character
coordinate system into the user coordinate system. TrueType fonts
maintain this value internally (for example, Apple TrueType fonts
use a 2048-unit coordinate system), so the PostScript coordinate
system transformation is the identity matrix.
Value for Type 42 fonts: [100100]
Note that certain PostScript programs (for example, program 16
in the PostScript Language Tutorial and Cookbook) incorrectly
assume that all PostScript fonts have a 1000-unit coordinate
system. These programs may exhibit incorrect behavior when
used with Type 42 fonts.
FontName name Optional. This entry is for information only. FontName is not
used by the PostScript interpreter.
Conventional value: PostScript name from the 'sfnt' name table
FontType integer
Required. Indicates where the information for the character
descriptions is found and how it is represented.
Value for TrueType fonts: 42
LanguageLevel integer
Optional. This integer indicates the minimum language level
required for correct behavior of the font. This entry is for
information only. LanguageLevel is not used by the PostScript
interpreter.
Default value: 1
UniqueID integer
Optional. An integer in the range 0 to 16777215 (224 – 1)
that uniquely identifies this font for the purposes of caching
character bitmaps and metrics.
Conventional value: the lower 24 bits of the 'sfnt' checksum.
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